Part of the narcissism comes in because because he want to broadcast not communicate. I don't disagree that email can be a distraction, but only answering your email once a week makes communication impossible. Twitter would be useless (more than I already believe it is) if everyone decided to use it as broadcast medium and never read anything. What's the point if there are no readers?

You can do broadcasting if your Linus Torvalds, if not you might need to check your email a little more frequently.